卤代邻羟苄基谷氨酸(酯)的合成、表征及抑菌活性

分别用氯代水杨醛、溴代水杨醛与L-谷氨酸及其酯反应，首先制得水杨醛缩谷氨酸类席夫碱(2)，再经硼氢化钠还原制得邻羟苄基取代谷氨酸及其酯(3)，化合物的结构经IR、1H NMR、MS与元素分析表征确认. 测试表明，在质量浓度为0.05%时，卤代邻羟苄基谷氨酸对大肠杆菌具有高的抑菌活性，抑菌率高达97%，对白色念珠菌、金黄色葡萄球菌的抑菌效果较差，但其甲酯化产物卤代邻羟苄基谷氨酸甲酯对白色念珠菌具有高的抑菌活性，抑菌率高达100%，对大肠杆菌、金黄色葡萄球菌的抑菌效果较差，说明该类衍生物对菌株的抑杀作用具有明显的专一性和特异性，氯代邻羟苄基谷氨酸甲酯、溴代邻羟苄基谷氨酸甲酯是白色念珠菌的优良抗菌化合物。

Synthesis, Characterization and Antibacterial Property of Halogenated o-hydroxybenzyl-glutamates and there esters

The salicylaldehyde-type glutamate Schiff bases(Ⅱ) were obtained first by the reactions of chlorinated salicylaldehyde, bromide salicylaldehyde and L-glutamates and their esters, and then the schiff bases were reduced by NaBH_4 to produce halogenated o-hydroxybenzyl-glutamates and their esters(Ⅲ). The structures of the products were confirmed by ~1H NMR, IR, MS and elemental analysis. The results of preliminary bioassay show that at a mass concentration of 0.05%, p-halo-o-hydroxybenzyl-glutamates had obvious antimicrobial activity against E.coli, with an inhibition rate of as high as 97%, but has less effective to M.albicans or S.aureus. The methyl esters, such as p-halo-o-hydroxybenzyl-glutamate methylesters, had obvious antimicrobial avtivity against M.albicans, with an inhibition rate of as high as 100%, but was less effective to E.coli or S.aureus, indicating that the antibacterial properties of the title compounds have an obvious selecti-vity and specificity. p-Chloride-o-hydroxybenzyl-glutamate methylester, p-bromide-o-hydroxybenzyl-glutamate methylester are fine antibacterial compounds for M.aureus.